1. Download the GEF (Dependency package):
Http://www.eclipse.org/downloads/download.php?file=/tools/gef/downloads/drops/3.7.2/R201201171043/GEF-ALL-3.7.2.zip
After downloading and decompressing, open the Eclipse folder in the package, and copy the contents of the features and plugins two folders to the features and plugins two folders in the Eclipse installation directory, respectively.
2. Download HTMLEditor
Http://amateras.sourceforge.jp/cgi-bin/fswiki_en/wiki.cgi?page=EclipseHTMLEditor
Click here Download in the Red box location to get Tk.eclipse.plugin.htmleditor_2.1.0.jar this jar package and copy it to the Plugins folder in the Eclipse installation directory. Restart Eclipse
3. Modify the default opening method for HTML files in eclipse
Window->preferences->general->editors->file Associations
Click HTML, select Amateras HTML Editor, and click on the Default,ok on the right to complete the configuration.